In its simplest form, a hand operated back scratcher comprises an elongated handle or shaft which has affixed to one end means for engaging the back. In operation, the free end distal the back-engaging means is grasped in the hand and the back-engaging means is placed either over the shoulder or under the arm, pressed against the back and reciprocated. By pressing the back-engaging means against the back, typically through a moment imparted to the shaft by manipulation with the grasping hand, a massaging or scratching action results.
The simple back scratching device heretofore known has had many attendant inconveniences associated therewith. For example, the natural tendency is to grasp the back scratcher in such a manner that the back-engaging means is not in proper alignment with the back so that either the elbow and/or wrist must be in an awkward position to permit proper alignment, or the back scratcher must be regrasped. For example, in U.S. Pat. No. 4,091,805 there is illustrated an electrically vibrated back scratcher in which the handle is provided with a "bicycle grip", that is, a plurality of grooves corresponding with the four fingers of the hand with which the handle is grasped. As shown in that patent, when the device is operated over the shoulder, proper engagement of the back by the back-engaging means when the handle is grasped as intended is only effected with a positioning of the elbow and arm to the side of the user substantially in the plane of the torso.
Another inconvenience with back scratchers heretofore known is that the handle and the back-engaging means are connected by a long, straight shaft. When such a back scratcher is operated over the shoulder, extension of the arm is required so that the shaft will clear the shoulder. Similarly, when prior art back scratchers are operated under the arm, the elbow and arm must be positioned inconveniently behind the plane of the torso to permit clearance of the shift across the side of the torso. In either mode of operation, the extension of the arm required to reach the nearer portion of the back is made more extreme by the length of the shaft. Often, this extreme reaching with known back scratchers is nearly as difficult as scratching the back without the use of such a device.
It is also desirable to be able to store a back scratcher conveniently, safely and attractively when the device is not in use. One manner of storage has been to hang the device on a projection extending from a wall, such as a nail, for example, through a loop or eye formed in the handle of the device such as is shown, for example, in U.S. Pat. No. 869,250 and in U.S. Pat. No. Des. 266,280. Another method has been to form a base on the handle on which the device may be rested upright while not in use as illustrated in U.S. Pat. No. Des. 260,694. However, such a base must have a substantial surface area and/or be weighted if the back scratcher is not to be too easily tipped over when stored in the upright position. Such a base inconveniences the operation of the back scratcher because of the extra weight which must be lifted and/or because of the tendency of the base to interfere with the movement of the hand during manipulation of the device.
Still another inconvenience associated with back scratchers is that the back-engaging means tends to become worn with use such that the massaging of the back becomes more difficult, because of the increased pressure which must be applied to obtain satisfaction, eventually necessitating replacement of the back-engaging means or the entire back scratcher. One attempt at solving this problem is described in U.S. Pat. No. 1,212,443 in which the head of the back scratcher is provided with a plurality of rounded projections formed on opposite edges of a channel. With this device, when the rounded projections become worn from use, the head may be reconditioned by running a file through the channel and between the rounded projections. However, it is believed that such rounded projections when moved across the back are not as satisfying when a shirt is worn. Moreover, the rounded projections on the device described in U.S. Pat. No. 1,212,443 present a flat surface to the back and it is difficult to engage the concave surfaces of the back therewith, such as the small of the back, without twisting the device with the hand in an awkward position. In addition, the head and the handle are connected by screw threads which have a tendency to unscrew when the head is rotated against the handle in a counter-clockwise direction as might occur when it is twisted to engage the concave portions of the back.